Guy Grunfelder

A Dual Band MIMO Channel Sounder at 2.2 and 3.5 GHz

The use of antenna arrays for the future wireless systems is a good solution to increase data rates and quality of service. The performances of these systems are very dependent on the propagation channel between the transmitter and receiver sites. That makes the spatio-temporal characterization and modeling of the channel very crucial in this context. In this paper, we present a wideband MIMO (multiple-input multiple-output) channel sounder at 2.2 and 3.5 GHz. It allows measuring the double directional properties of the propagation channel at emission and reception. Different architectures of antenna arrays are presented. The two high resolution algorithms unitary ESPRIT and SAGE are applied on measurement data to obtain more resolution and accuracy. Beam patterns measurement results for antenna arrays calibration in anechoic chamber are presented. Finally, some propagation measurement results are illustrated.

Performance analysis of a hierarchical shipboard Wireless Sensor Network

Wireless Sensor Networks (WSN) have recently gained a great attention in several applications such as environmental monitoring and target tracking. Applying this technology to shipboard monitoring systems may be a cost-effective solution to reduce the cost of wires installation and maintenance. However, wireless communications on board ships may be severely obstructed by the metallic structure of bulkheads. In this paper, we analyze the efficiency of a shipboard WSN by measurement and simulation. A measurement campaign is conducted to study the radio wave propagation and to verify the feasibility of a WSN on board a ship. Based on the measurement results, a hierarchical group-based topology for a large-scale shipboard WSN is proposed. A realistic simulation model of the ship, taking into account the environment particularities, is then performed using OPNET network simulator. Performance of the WSN architecture is evaluated using the ZigBee model. Measurement results show the feasibility of WSN technology on board ships, while simulation results show significant performance of proposed architecture in terms of end-to-end delay and packet delivery ratio.

Wireless Sensor Network on board vessels

Wireless Sensor Networks (WSNs) have been used recently in different applications such as environmental monitoring and target tracking. Few papers have investigated the viability of this technology on board ships. We study in this paper the possibility of replacing the wired shipboard monitoring system by a WSN. This environment has a specific metallic structure which makes the wireless communication more difficult than in other classical indoor and outdoor environments. Two types of experiments have been carried out on board a ferry-type boat during sailings and stopovers. The first experiment consists of point-to-point measurements using ZigBee-based equipments and the second one consists of deploying and testing a WSN on board the ferry. These tests have been conducted during realistic conditions on board the ferry, which give a high level of reliability to results with respect to the earlier experiments on board ships moored to the harbor. In spite of the harsh metallic structure and the dynamic environments on board the ferry, the obtained results have shown that the wireless solution may be a cost-effective alternative to the huge amount of cables used currently to connect sensors to central control units.

MIMO Channel Sounder at 3.5 GHz: Application to WiMAX System

The use of antenna arrays at emission and reception seems to represent a prominent solution for future wireless systems, it improves data rates and enhances the quality of service. The performance of these systems depends mainly on the propagation channel. Therefore, channel’s characterization and modeling are crucial. In this document, we present a MIMO (Multiple Input Multiple Output) channel sounder at 3.5 GHz developed at IETR. One of the applications operating at this frequency is the WiMAX system. Different antenna arrays architectures are designed and calibrated at 3.5 GHz for high resolution MIMO channel sounding. Antenna arrays beam patterns are measured and calibrated. The importance of this work is shown by ESPRIT simulations. Propagation measurement results are needed to obtain realistic MIMO channel models.

Application of Wireless Sensor Network for the Monitoring Systems of Vessels

This chapter studies the feasibility of WSN on board ships. Several measurement campaigns are conducted on board a ferry-boat to verify the possibility of wireless communications between ship parts and to analyse the performance of WSN on board. These measurements aim at determining path loss models for typical shipboard environments and testing the possibility of wireless communication between adjacent rooms or adjacent decks. Using the results of these experiments, a WSN is tested on board the ferry. The results obtained from the measurement campaigns are then used to propose an architecture for a large-scale shipboard WSN. As the network test uses a limited number of nodes, the full monitoring system based on the proposed architecture is simulated using a network simulator.

Single carrier architecture for high data rate wireless PAN communications system

A 60 GHz wireless Gigabit Ethernet (G.E.) communication system is developed at IETR. As the 60 GHz radio link operates only in a single-room configuration, an additional Radio over Fibre (RoF) link is used to ensure the communications in all the rooms of a residential environment. The realized system covers 2 GHz bandwidth. Due to the hardware constraints, a symbol rate at 875 Mbps is attained using simple single carrier architecture. In the baseband (BB) processing block, an original byte/frame synchronization process is designed to provide a smaller value of the preamble missing detection and false alarm probabilities. Bit error rate (BER) measurements have been realized in a large gym for line-of-sight (LOS) conditions. A Tx-Rx distance greater than 30 meters was attained with low BER using high gain antennas and forward error correction RS (255, 239) coding.

Radio Wave Propagation Characterization between Adjacent Decks on Board Ships

The objective of this paper is to characterize the electromagnetic waves propagation between adjacent decks on board a ship. First, narrowband measurements were conducted at 2.45 GHz to study the radio coverage. Different configuration scenarios where considered. Then, double directional channel sounding was performed at 3.5 GHz to determine the propagation mechanisms and multipath parameters in this hostile environment. The aim of these measurement campaigns is to find a solution to maintain the connectivity of a wireless sensor network between different decks on a ship in spite of the metallic structure of decks.